1/*	$KAME: rthdr.c,v 1.19 2003/06/06 10:48:51 itojun Exp $	*/
2
3/*
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD$");
34
35#include <sys/param.h>
36#include <sys/types.h>
37#include <sys/socket.h>
38
39#include <netinet/in.h>
40#include <netinet/ip6.h>
41
42#include <string.h>
43#include <stdio.h>
44
45/*
46 * RFC2292 API
47 */
48
49size_t
50inet6_rthdr_space(type, seg)
51	int type, seg;
52{
53	switch (type) {
54	case IPV6_RTHDR_TYPE_0:
55		if (seg < 1 || seg > 23)
56			return (0);
57#ifdef COMPAT_RFC2292
58		return (CMSG_SPACE(sizeof(struct in6_addr) * (seg - 1) +
59		    sizeof(struct ip6_rthdr0)));
60#else
61		return (CMSG_SPACE(sizeof(struct in6_addr) * seg +
62		    sizeof(struct ip6_rthdr0)));
63#endif
64	default:
65		return (0);
66	}
67}
68
69struct cmsghdr *
70inet6_rthdr_init(bp, type)
71	void *bp;
72	int type;
73{
74	struct cmsghdr *ch = (struct cmsghdr *)bp;
75	struct ip6_rthdr *rthdr;
76
77	rthdr = (struct ip6_rthdr *)CMSG_DATA(ch);
78
79	ch->cmsg_level = IPPROTO_IPV6;
80	ch->cmsg_type = IPV6_RTHDR;
81
82	switch (type) {
83	case IPV6_RTHDR_TYPE_0:
84#ifdef COMPAT_RFC2292
85		ch->cmsg_len = CMSG_LEN(sizeof(struct ip6_rthdr0) -
86		    sizeof(struct in6_addr));
87#else
88		ch->cmsg_len = CMSG_LEN(sizeof(struct ip6_rthdr0));
89#endif
90
91		bzero(rthdr, sizeof(struct ip6_rthdr0));
92		rthdr->ip6r_type = IPV6_RTHDR_TYPE_0;
93		return (ch);
94	default:
95		return (NULL);
96	}
97}
98
99/* ARGSUSED */
100int
101inet6_rthdr_add(cmsg, addr, flags)
102	struct cmsghdr *cmsg;
103	const struct in6_addr *addr;
104	u_int flags;
105{
106	struct ip6_rthdr *rthdr;
107
108	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
109
110	switch (rthdr->ip6r_type) {
111	case IPV6_RTHDR_TYPE_0:
112	{
113		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
114		if (flags != IPV6_RTHDR_LOOSE && flags != IPV6_RTHDR_STRICT)
115			return (-1);
116		if (rt0->ip6r0_segleft == 23)
117			return (-1);
118
119#ifdef COMPAT_RFC1883		/* XXX */
120		if (flags == IPV6_RTHDR_STRICT) {
121			int c, b;
122			c = rt0->ip6r0_segleft / 8;
123			b = rt0->ip6r0_segleft % 8;
124			rt0->ip6r0_slmap[c] |= (1 << (7 - b));
125		}
126#else
127		if (flags != IPV6_RTHDR_LOOSE)
128			return (-1);
129#endif
130		rt0->ip6r0_segleft++;
131		bcopy(addr, (caddr_t)rt0 + ((rt0->ip6r0_len + 1) << 3),
132		    sizeof(struct in6_addr));
133		rt0->ip6r0_len += sizeof(struct in6_addr) >> 3;
134		cmsg->cmsg_len = CMSG_LEN((rt0->ip6r0_len + 1) << 3);
135		break;
136	}
137	default:
138		return (-1);
139	}
140
141	return (0);
142}
143
144/* ARGSUSED */
145int
146inet6_rthdr_lasthop(cmsg, flags)
147	struct cmsghdr *cmsg;
148	unsigned int flags;
149{
150	struct ip6_rthdr *rthdr;
151
152	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
153
154	switch (rthdr->ip6r_type) {
155	case IPV6_RTHDR_TYPE_0:
156	{
157		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
158#ifdef COMPAT_RFC1883		/* XXX */
159		if (flags != IPV6_RTHDR_LOOSE && flags != IPV6_RTHDR_STRICT)
160			return (-1);
161#endif /* COMPAT_RFC1883 */
162		if (rt0->ip6r0_segleft > 23)
163			return (-1);
164#ifdef COMPAT_RFC1883		/* XXX */
165		if (flags == IPV6_RTHDR_STRICT) {
166			int c, b;
167			c = rt0->ip6r0_segleft / 8;
168			b = rt0->ip6r0_segleft % 8;
169			rt0->ip6r0_slmap[c] |= (1 << (7 - b));
170		}
171#else
172		if (flags != IPV6_RTHDR_LOOSE)
173			return (-1);
174#endif /* COMPAT_RFC1883 */
175		break;
176	}
177	default:
178		return (-1);
179	}
180
181	return (0);
182}
183
184#if 0
185int
186inet6_rthdr_reverse(in, out)
187	const struct cmsghdr *in;
188	struct cmsghdr *out;
189{
190
191	return (-1);
192}
193#endif
194
195int
196inet6_rthdr_segments(cmsg)
197	const struct cmsghdr *cmsg;
198{
199	struct ip6_rthdr *rthdr;
200
201	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
202
203	switch (rthdr->ip6r_type) {
204	case IPV6_RTHDR_TYPE_0:
205	{
206		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
207
208		if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
209			return (-1);
210
211		return (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
212	}
213
214	default:
215		return (-1);
216	}
217}
218
219struct in6_addr *
220inet6_rthdr_getaddr(cmsg, idx)
221	struct cmsghdr *cmsg;
222	int idx;
223{
224	struct ip6_rthdr *rthdr;
225
226	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
227
228	switch (rthdr->ip6r_type) {
229	case IPV6_RTHDR_TYPE_0:
230	{
231		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
232		int naddr;
233
234		if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
235			return NULL;
236		naddr = (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
237		if (idx <= 0 || naddr < idx)
238			return NULL;
239#ifdef COMPAT_RFC2292
240		return (((struct in6_addr *)(rt0 + 1)) + idx - 1);
241#else
242		return (((struct in6_addr *)(rt0 + 1)) + idx);
243#endif
244	}
245
246	default:
247		return NULL;
248	}
249}
250
251int
252inet6_rthdr_getflags(cmsg, idx)
253	const struct cmsghdr *cmsg;
254	int idx;
255{
256	struct ip6_rthdr *rthdr;
257
258	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
259
260	switch (rthdr->ip6r_type) {
261	case IPV6_RTHDR_TYPE_0:
262	{
263		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
264		int naddr;
265
266		if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
267			return (-1);
268		naddr = (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
269		if (idx < 0 || naddr < idx)
270			return (-1);
271#ifdef COMPAT_RFC1883		/* XXX */
272		if (rt0->ip6r0_slmap[idx / 8] & (0x80 >> (idx % 8)))
273			return IPV6_RTHDR_STRICT;
274		else
275			return IPV6_RTHDR_LOOSE;
276#else
277		return IPV6_RTHDR_LOOSE;
278#endif /* COMPAT_RFC1883 */
279	}
280
281	default:
282		return (-1);
283	}
284}
285
286/*
287 * RFC3542 API
288 */
289
290socklen_t
291inet6_rth_space(int type, int segments)
292{
293	switch (type) {
294	case IPV6_RTHDR_TYPE_0:
295		if ((segments >= 0) && (segments <= 127))
296			return (((segments * 2) + 1) << 3);
297		/* FALLTHROUGH */
298	default:
299		return (0);	/* type not suppported */
300	}
301}
302
303void *
304inet6_rth_init(void *bp, socklen_t bp_len, int type, int segments)
305{
306	struct ip6_rthdr *rth = (struct ip6_rthdr *)bp;
307	struct ip6_rthdr0 *rth0;
308
309	switch (type) {
310	case IPV6_RTHDR_TYPE_0:
311		/* length validation */
312		if (bp_len < inet6_rth_space(IPV6_RTHDR_TYPE_0, segments))
313			return (NULL);
314		/* segment validation */
315		if ((segments < 0) || (segments > 127))
316			return (NULL);
317
318		memset(bp, 0, bp_len);
319		rth0 = (struct ip6_rthdr0 *)rth;
320		rth0->ip6r0_len = segments * 2;
321		rth0->ip6r0_type = IPV6_RTHDR_TYPE_0;
322		rth0->ip6r0_segleft = 0;
323		rth0->ip6r0_reserved = 0;
324		break;
325	default:
326		return (NULL);	/* type not supported */
327	}
328
329	return (bp);
330}
331
332int
333inet6_rth_add(void *bp, const struct in6_addr *addr)
334{
335	struct ip6_rthdr *rth = (struct ip6_rthdr *)bp;
336	struct ip6_rthdr0 *rth0;
337	struct in6_addr *nextaddr;
338
339	switch (rth->ip6r_type) {
340	case IPV6_RTHDR_TYPE_0:
341		rth0 = (struct ip6_rthdr0 *)rth;
342		/* Don't exceed the number of stated segments */
343		if (rth0->ip6r0_segleft == (rth0->ip6r0_len / 2))
344			return (-1);
345		nextaddr = (struct in6_addr *)(rth0 + 1) + rth0->ip6r0_segleft;
346		*nextaddr = *addr;
347		rth0->ip6r0_segleft++;
348		break;
349	default:
350		return (-1);	/* type not supported */
351	}
352
353	return (0);
354}
355
356int
357inet6_rth_reverse(const void *in, void *out)
358{
359	struct ip6_rthdr *rth_in = (struct ip6_rthdr *)in;
360	struct ip6_rthdr0 *rth0_in, *rth0_out;
361	int i, segments;
362
363	switch (rth_in->ip6r_type) {
364	case IPV6_RTHDR_TYPE_0:
365		rth0_in = (struct ip6_rthdr0 *)in;
366		rth0_out = (struct ip6_rthdr0 *)out;
367
368		/* parameter validation XXX too paranoid? */
369		if (rth0_in->ip6r0_len % 2)
370			return (-1);
371		segments = rth0_in->ip6r0_len / 2;
372
373		/* we can't use memcpy here, since in and out may overlap */
374		memmove((void *)rth0_out, (void *)rth0_in,
375			((rth0_in->ip6r0_len) + 1) << 3);
376		rth0_out->ip6r0_segleft = segments;
377
378		/* reverse the addresses */
379		for (i = 0; i < segments / 2; i++) {
380			struct in6_addr addr_tmp, *addr1, *addr2;
381
382			addr1 = (struct in6_addr *)(rth0_out + 1) + i;
383			addr2 = (struct in6_addr *)(rth0_out + 1) +
384				(segments - i - 1);
385			addr_tmp = *addr1;
386			*addr1 = *addr2;
387			*addr2 = addr_tmp;
388		}
389
390		break;
391	default:
392		return (-1);	/* type not supported */
393	}
394
395	return (0);
396}
397
398int
399inet6_rth_segments(const void *bp)
400{
401	struct ip6_rthdr *rh = (struct ip6_rthdr *)bp;
402	struct ip6_rthdr0 *rh0;
403	int addrs;
404
405	switch (rh->ip6r_type) {
406	case IPV6_RTHDR_TYPE_0:
407		rh0 = (struct ip6_rthdr0 *)bp;
408
409		/*
410		 * Validation for a type-0 routing header.
411		 * Is this too strict?
412		 */
413		if ((rh0->ip6r0_len % 2) != 0 ||
414		    (addrs = (rh0->ip6r0_len >> 1)) < rh0->ip6r0_segleft)
415			return (-1);
416
417		return (addrs);
418	default:
419		return (-1);	/* unknown type */
420	}
421}
422
423struct in6_addr *
424inet6_rth_getaddr(const void *bp, int idx)
425{
426	struct ip6_rthdr *rh = (struct ip6_rthdr *)bp;
427	struct ip6_rthdr0 *rh0;
428	int addrs;
429
430	switch (rh->ip6r_type) {
431	case IPV6_RTHDR_TYPE_0:
432		 rh0 = (struct ip6_rthdr0 *)bp;
433
434		/*
435		 * Validation for a type-0 routing header.
436		 * Is this too strict?
437		 */
438		if ((rh0->ip6r0_len % 2) != 0 ||
439		    (addrs = (rh0->ip6r0_len >> 1)) < rh0->ip6r0_segleft)
440			return (NULL);
441
442		if (idx < 0 || addrs <= idx)
443			return (NULL);
444
445		return (((struct in6_addr *)(rh0 + 1)) + idx);
446	default:
447		return (NULL);	/* unknown type */
448		break;
449	}
450}
451